Sometimes the problem is not just a stray hoof that sets the trap off as the deer, cow or elk walks down the trail. They are attracted to the smell of urine and lure. I had to relocate several traps that were near elk trails especially because they actively searched for the sets and pawed and trampled them to get at the attractants. At times deer, goats, and and cattle have done the same. Have not had any experience with horses doing it, but haven't trapped near them either. Maybe they smell salt in the urine or lure and that is what they are after.

Paskinner, your mail box is maxed out.
Don't feel too bad about cats walking on by. I seen in the snow where a bobcat came up to a fisher cubby that was freshly baited with fresh beaver meat and simply saw where it sat down and rested. Then the sign showed the cat simply walked by the fresh meal. I was not asking the cat (or fisher) to go up hill or down, it was a level approach, in a natural cubby. Some times those rascals are just being cats.

The cat was hunting, not just going from point A to point B. By paralleling the trail he can ambush a critter on it. A faint trail parallel to a predominate trail is an excellent place to snare a cat, even better if it is a little higher than the larger trail. For both his own safety and for ambush the cat wants to see without being seen.

In "Newt's World"
Here in South Jersey. Where a good buck will weigh only 90#.Lots of yearlings will weigh 20#-30# in trap'n season. Any horizonal pole higher than 12" will put more deer in your set, than not.

Johnny Thorp- "A bobcat is like a pot head. He has nothing to do all day. And all day to do it."
When snaring in the southern states. I cought most of my snared cats. On trails that looked like coon trails,to a untrained eye.

"Rabbit" trails around old brush piles are likely to hit

Just a note,I used the 16",horizontal pole in the East as well,where the deer weren't big and no problems.The key is,leave it clear over the pole for deer to go over and a place to go around,if they want to.If it is a straight section of trail,cats will go straight through.16" is lower than a deer's belly.Make sure the pole is horizontal,not slanted,and blocked in tight.

The OP is talking about traps,not snares.Even if a deer scooted under,he would just have a snipped trap.

You can also add a second pole,parallel to the first and a few inches apart,trap directly under,to really keep the deer's feet off the trap.

This is what I surmised. A few places I'm sure the cats are the only critters that walk those faint paths. Other places there are buck trails that parallel the deer trails.